Refillable cartridge fuse



Aug. 17 1926. I 1,596,436

. L. KELLNER REFILLABLE CARTRIDGE FUSE Filed April 1'7, 1925 Patented Aug. 17, 1926.

UNITED STATES PATENT OFFICE.

LOUIS KELLNER, OF CHICAGO, ILLINOIS, ASSIGNOR TO CHICAGO FUSE MFG. CO., OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

REFILLABLE CARTRIDGE FUSE.

Application filed April 17, 19 25. Serial No. 23,785.

This invention relates to refillable cartridge fuses of the knife blade type, and the general object of this invention is to provide novel means for securing the knife blades of the fuse in fixed position with respect to each other and to the casing.

A more specific object is to provide an annular compressible clamping element for each blade which embraces the edge of a disk fixed on the blade and is arranged to be engaged between and compressed by the end of the cartridge casing and the cap thereon. 1

Still another object is to provide a blade fixing device which is operable to release the blade merely' on loosening the fuse cap without removing the cap from the casing.

Further objects and advantages of the invention will be understood from the following detailed description taken in connection with the accompanying drawings, in which Figure 1 illustrates a longitudinal section of a fuse embodying the invention.

Fig. 2 is a similar section of the fuse taken in a plane at right angles to the plane of Fig. 1.

F 3 is a cross section of the fuse taken on the line of Fig. 2.

Fig. 4 is a perspective view of the an nular clutch element.

Fig. 5 is a cross section of the ring of Fig. 4 taken in the plane of line 5--5 thereof.

Fig. 6 is an enlarged detail cross section of the left hand end of the fuse shown in Fig. 1.

. Vhile I have shown in the drawings and will herein describe in detail the preferred embodiment of the invention, I desire to have it understood that this disclosure is given for the purpose of representing but one specific way of carrying out the invention and it is .not intended as a limitation thereof to the construction disclosed. I aim in the appended claims to cover all modifications and alternative constructions falling within the scope of the invention as limited by the state of the prior art.

In the preferred embodiment of the invention herein shown, the cartridge fuse comprises a tubular casing composed in the present instance of insulating material 7. Projecting from each end of the casing and secured thereto are knife blades 8 forming terminals for the fuse. The blades pass into the casing wherein ends 9 are electrically connected by a fusible element 10, in the present instance this being a flexible strip of ribbon-like metal. Any suitable and Well known means of providing the connection may be used as, for example, the bolts 11, washers 12 and the nuts 13. 1 This type of fuse of course requires that at least one of the blades be able to pass through the casing. However, it is preferable that each. end du plicatethe other as herein illustrated.

Means is provided to secure each knife blade 8 rigidly to the casing and non-rotatable therewith, each blade being fixed with 1 reference to the other and both blades lying preferably in the same plane, as illustrated, and as commonly required for this type of fuse.

Each end of the cartridge casing 7 has a metallic head 14: threaded thereon and secured by a rivet 15 passing through the threaded portions of the head and casing. The end 16 of the head 14 is externally threaded to receive an annular cap 17 having an internal flange 18, the cap 17 being so constructed that it passes freely over the blade 8.

The knife blades 8 each have a disk 19 thereon which is non-rotatable and rigid with respect to each blade, the disk being provided to close the end of the casing. In the present instance the periphery of the disk lies slightly within the edges of the blades 8, the diameter of the disk being less than the width of the blade. The inner ends 9 of the blades 8 are narrower in width and pass through slots in the disk forming shoulders 20 in the blad which bear on the outer face of each disk.

Means is provided to clamp the disk 19 in a fixed position between the head 14 and the cap 17. In the present instance this is in the nature of a clutch element which tightens its grip upon th periphery of the disk as the cap is screwed onto the head. To cause the clutch action interengaging beveled or cone-like surfaces are provided. A clutch element in the form of a split ring 21, shown in detail in Figs. 4 and 5,

surrounds the peri hery of the disk. The ring has broken en s 22 and 23, in the form of a V. The V shape not only serves to.

maintain the ring in an undistorted condition but also provides a gas vent from the fuse which is baffled in distinction from that which would be formed by straight cut ends of the split. ring. The periphery of th disk 19 is provided with two conical surfaces or beveled edges designated 2%: and Likewise the inner side of the ring has conical surfaces similarly designated. In the present instance the surfaces and 2 intersect thus forming a V-shaped annular groore this i in the split ring 21. The outer sides g as shown 27 and 2S and may be substantially parallel with the insi surfaces 24 he inner the head it (l6 surace of a conical surface engageable with :i-ng surface 28 and the inner surface he flange 18 has a conical surface 30 enwith the ring surface 2?. By sehe cap 17 onto the head 14 the ring osed and firmly grips the disk it) holding it fixedly in place between the head and cap Of course it is to be understood that one or more of the conical surfaces may be omitted so long as th requisite clamping action is obtained, according to the specific co lruction adopted.

ilthough the disk may be firmly clamped by the ring 21 interposed between the cap 17 and head l l, it would ordinarily be held a rinst rotation by the construction so far retited. only a; friction. Usher and positiv loci-ting means is provided to prevent relative rota ion between the k ife blades 8- and the casing 7. Such meansis provided b ing to the ring such a character that it inay be locked nonrotatably both to the knife blade structure and the casing structure. A tongue or linger 31 is provided rigid with the ring and this is locked to the casing. A recess is provided in the structure preferably in the insulating tube 4' adjacent the head le't. Into this recess tits a hooked portion formed on the finger cl. The engagement of the hook in the recess prcrents rotation of the ring relative to the casing. The outer side or flange 3i of the ring .21 is smaller in diam er than the width of the blade 8, not only in the closed but preferably in the normal on ianded condition of the ring. In order to allow -e ring to clutch the disk 1 preferably pro. periphery of the ring to receive the edges of the blad 8'. These notches thus hold the blade non-rotatable with respect to the ring which being non-rotatable with respect to the casing holds the blade 8 non-rotatable with respect to the casing. The slanting sides of the ring may be made symmetrical. but it is preferable to have the inner s thereof, having no slots like the eo6 slots suliiciently large in diameter in the expanded condition to permit the blade 8" denotches formed in the to pass through the expanded ring without the exercise of a force to expand the ring.

lVith this construction the cap can be loosened, the ring expanded and the blade and disk inserted through the end opening of the tube in spite of the presence of the cap and the ring. The disk 19 has its greatest diameter such that the disk will 'eadily lit into the groove 26. of the clutch ring with little or no forcing of the ring. This requires that the largest diameter of the disk be substantially the same as the smallest internal diameter of the expanded rin These relations are, of couise, imerial to the proper operation of the device but are preferred for convenience and eat in manipulation of the parts for assembly purposes.

In using fuse of this character assuming it to have been blown, the operator will first loosen the caps 17 thus releasing each of the blades 8 which will come outof the casing separately because the fusible element 10 is broken. If the rings areso constructed that a slight expansion will completely release the blades then it will not be necessary to remove the-caps completely. Otherwise, if the caps are removed the rings 21 may cling to the blade so that one may readily remove them easiest orer the smaller ends of the blades 8. Depending upon the relative size of the ring and disk and the degree of normal expansion, itinay or may not. be necessary to spring the rings slightly for removal. Of course, it is preferable when so removed, that they do not fall olf as this fact will eliminate a certain degree of handling of the rings.

A new fusible element 10 is connected between the two blades 8 in a normal manner.

he blades connected to the fusible elel0 require that in lining the blades into the casing one end of the connected blade structure should pass through the casing.

In the preferred construction when the are retained between the loosened ps the blade and fuse structure can be d into the fuse cartridge to position hin the rings for clumping. In case the ring is so constructed that it clings to the disk, the end of the fuse and blade structure not passing through the casing shall, of course be the one having the ring over the disk. After insertion of the one blade through the casing the remaining ring 21 must he slipped over the blade 8 from the free end by slight expansic-n thereof. If the ring has the suitable dimensions, when the unslotted flange passes off the blade edge the ring will spring into place over the disk and the edges of the blade will lie in the slots 35. Both ringswill now be in proper position to clutch the disks 19 and the slots 35 of the rings will engage the edgesof the blades 8;

[all

I I l The blades are turned into the same plane whereupon the fingers 31 permit the hooks 33 to move intothe recess 32. The caps 17 are then screwed up on the heads 14 to compress and clamp the clutch elements.

It will be seen by the above description of the device illustrating the invention that I have provided a cartridge fuse of the renewable type in which the contact blades are fixedly mounted in the casing in a predetermined lanar relation, that a mounting member in the form of a clutch element for each blade is provided which not only fixedly clamps the blades but positively locks the blades against rotation with respect to each other and with respect to the casing. And further, it will be seen that I have provided 'a structure which in the preferred relation of the parts permits removing and replacing the fuse blades by merely loosening the caps without removing them from the cartridge casing. It will, of course, be understood that other embodiments of the invention are contemplated as will appearfrom the statement of the invention, as found in the appended claims.

I claim as my invention:

1. A cartridge fuse comprising, in combination, a tubular casing, annular caps adapted to be screwed onto the ends of said casin blades for said fuse adapted externa ly of the casing for mounting the fuse and internally of the casing for secur in a fusible element between the blades, said blades being capable of passage through said casing and said annular caps, a disk carried by each blade rigid therewith, to close the ends of the casing, each disk having a V-shaped beveled edge, an internal annular flange on each cap, said flange and the ends of the casing having conical beveled edges adapted to oppose each other when the cap is screwed to the casing, a split clutch ring having inner and outer conical faces on both sides of the ring, said inner faces being adapted to enclose the disk and said outer faces being adapted to be engaged by the conical faces of the cap and end to close the ring about said disk, said ring being slotted at one edge to encompass the edge of the blade in the clutching position of the ring, and a projection on said ring extending into a recess in said casing whereby the blade is locked non-rotatably to the casing.

2. A cartridge fuse having, in combination, a tubular casing, an annular screw cap for the end of said casing, a terminal adapted to be secured between said cap and said end, said terminal having a knife portion externally of the casing extending through said annular cap for mounting the fuse, an internal portion for connecting thereto a fusible element, and a disk to close the end of said casing, means surroundingsaid dlSk to clamp said disk between said end and cap, and other means to lock said terminal in a predetermined non-rotatable relation with respect to said casing.

3. A cartridge fuse having, in combinat on. .a tubular casing, an annular screw cap for the end of said casing, a terminal adapted to be mounted between said cap and the end of said casing, said terminal having a knife portion externally of the casing extending through said annular cap for mounting the fuse and an internal portion for connecting thereto a fusible element, and lint-Fag also a disk for closing the end of said casing, clutch means surrounding said disk and operable by screwing the cap onto the casing to clamp the disk, means to hold said clutch means non-rotatably with re spect to the casing, and other means to hold said terminal non-rotatable with respect to the clutch means.

i. A cartridge fuse comprising, in combination, a tubular casing, a knife blade terminal adapted to be mounted in the end of said casing, an annular cap adapted to be screwed onto said end over said knife blade terminal, a disk carried by said blade terminal rigid therewith, said blade and disk being free to pass through the casing, a split ring adapted when expanded to pass over said blade and when contracted to be interposed between said disk and said casing to prevent the passage of the disk into said casing, whereby said cap may screw onto said casing to secure said diskthcrebe tween, and means to lock said ring to both the blade and the casing.

A cartridge fuse having. in combination, a tubular casing, a blade terminal ha"- ing a width less than the internal diameter of the casing whereby said blade may pass through said casing, a disk carried by said blade rigid therewith to close the end of said casing, an annular cap fitting over the blade adapted to be secured to the end of the casing. the periphery of the disk having a beveled or conical surface, and a split ring having a V-shaped groove internally to clutch the disk when contracted about the periphery of the disk and having also a beveled or conical surface externally adapted to be clamped between and contracted by the cap and easing when secured tightly together.

6. A fuse having in combination, a tubir lar casing, a knife blade terminal, a disk rigid with said terminal adapted to be positioned to close the end of the casing, an annular can adapted to be screwed to the end of said casing over said terminal, and a contractile retaining ring arranged to enclose said disk, said ring being further adapted to be positioned between the cap and the casing, said ring being contracted by screwing the cap to the casing by the 

